Liquid flow meters utilizing nutating disks have long existed in the prior art. These devices have used various means to transmit the oscillating input to an output readable by the user. These devices have been designed with the industrial user in mind as opposed to residential or commercial users. Many of these prior art devices are not easily connectable to common household plumbing and are of a size and shape which makes their use in the residential or commercial setting impractical.
Certain areas of this country, especially the West, have recognized the problems associated with water conservation. In fact, certain municipalities which heretofore have not required the use of water meters are now so requiring at least in new residences and it is readily foreseeable that the installation of such meters in all residences will become mandatory. More importantly, residences already provided with water meters are now subject to scrutiny with respect to consumption characteristics which, if excessive, will cause municipalities to put restrictive-use devices in the conduit leading to excessive users to curb profligate water use.
This invention, while utilizing some similar components as those existing in the prior art, measures the flow of liquids in a new and useful manner more appropriately suited to the residential or commercial user. Lightweight materials are used and a simplified structure is employed with simple interconnections of standard sizes and shapes.
The following patents reflect the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter.
______________________________________ INVENTOR PATENT NO. ISSUE DATE ______________________________________ Thomson, et al. 375,023 December 20, 1887 Tilden 486,992 November 29, 1892 Thomson 514,171 February 6, 1894 Treff, et al. 2,921,468 January 19, 1960 Southall 3,442,126 May 6, 1969 Branitzky Re 28,000 April 30, 1974 Aigner 4,232,550 November 11, 1980 ______________________________________
The patent to Thomson teaches a water flow meter whose chamber is along side the conduit being measured. Also, a bowl-shaped nutating disk is utilized to measure liquid flow. The device of this invention is distinguishable from Thomson in that the nutating disk of this invention is a flat disc rather than a bowl-shaped disk. Furthermore, the device of this invention utilizes a photo-optical transducer to measure oscillation of the nutating disk.
The invention to Southall teaches, in one embodiment, a nutating disk to measure fluid flow. The nutating disk in Southall is oriented such that the disk axis (which is perpendicular to the disk) is parallel with the direction of liquid inlet and liquid outlet. The device of this invention is distinguishable in that the disk axis is perpendicular to the nutating disk and also is perpendicular to the inlet and outlet of the liquid being measured. Also, the Southall patent discloses the use of a magnetic sensor to measure disk oscillation, whereas the device of this invention uses a photo-optical device.
The patent to Tilden teaches a liquid flow meter utilizing a nutating disk which has a tapering cross-section. The Tilden device is shaped for utilization within a substantially cylindrical chamber. The device of this invention utilizes a flat nutating disk within a housing having a greater thickness at extremities than at the center of the nutating disk. Furthermore, the device of this invention utilizes a photo-optical sensor to register oscillation of the nutating disk as opposed to a mechanical linkage as disclosed in Tilden.
The patent to Treff discloses a liquid meter utilizing a nutating disk which has a magnetic sensor connected to a meter display having a plurality of dials connected to gears. The device of this invention is distinguishable from Treff in that it utilizes an electric readout device. An electric readout provides greater flexibility to the user of the meter in recording fluid flow over a period of time. Also, the present invention is of a simple lightweight construction more easily utilizable in a residential or commercial environment.
The patent to Aigner is of interest in that it discloses (in an alternative embodiment) the use of an infrared diode and a photo-transistor for recording the oscillation of a nutating disk incorporated therein. The Aigner patent utilizes a nutating disk which fits frictionally within a housing without any roller bearings on any surfaces. The device of this invention is distinguishable from Aigner in that a meter is provided for displaying the measurements of the device in a variety of useful ways and also has a nutating disk supported on some surfaces with roller bearings and on other surfaces with materials allowing smooth sliding of the nutating disk thereagainst.
The remainder of the prior art cited above but not specifically distinguished diverge more starkly from the present invention than those references cited above which were specifically distinguished. The device of this invention displays patentable novelty when compared to each of the devices in the prior art disclosed hereinabove.
It is stipulated, however, that none of these references teach singly, nor render obvious when combined in any conceivable, perceivable manner, the nexus of this invention as disclosed in greater detail hereinafter.